shelby@shelbyshreve.com

Hello,

Wondering if I could get some advice from you kind folks here. Over
the last year and a half I have experienced intermittent problems with
my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
kick in at maybe 5 mph right before the stop. It might do it a few
times in a row then disappear for months at a time. Everything checks
out when I take a look at the braking system, so I was stumped. I even
have had the braking system professionally inspected a couple times
right after the behavior, but everything checks out fine.....so I
guessed it's one of those 'wait until it gets worse' kind of things.

Lately however, it seems to be increasing in frequency. Yesterday
after exhibiting the same behavior the ABS light came on. This leads
me to think that it might be getting worse. Any ideas or
troubleshooting advice for fixing this?
Thanks,
Shelby

DougW

shelby did pass the time by typing:
> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?

Two things can do this.
1) ABS sensor just slightly out of cal (but still within spec)
That will pass tests but act up. Generally it occurs just as you say, right before the stop.
But first do step 2. If step 2 doesn't work have the mechanic take a real close look
at the sensors because one of them is out of calibration (or covered in metal filings)

2) Grime in the ABS computer connector (or the abs sensor connectors)

To clean the ABS sensors use a paper towel and a stick.
While your in there make sure the tone ring (toothed ring by the sensor)
isn't missing any teeth.

(based on the 93 ZJ)
Clean the connector on your ABS computer.
http://revbeergoggles.com/Fixes/computer-abs.jpg

Get a plastic bag, paper towel, a q-tip or ten, a zip tie
and some contact cleaner that's safe for plastic and a
bit of dilectric grease (sparkplug boot grease)

Disconnect the battery
Lift the latch and disconnect the harness
Take the airbox top and filter off. (this is your work sink)

Put the plastic bag in the airbox bottom, and some paper towels
now move the connector over the sink and open the shield, tap out
all the dirt and spray with cleaner (make sure it doesn't get on
the paint and if it does wipe it up pronto, it's like paint remover)

Clean the contacts on the ABS computer.

Put the shell back on and use the ziptie if the one on there broke.

Pack the dilectric grease into the connector and put it back on the
computer.

This fixes about 80% of all ABS light problems.

--
DougW

DougW

shelby did pass the time by typing:
> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?

Two things can do this.
1) ABS sensor just slightly out of cal (but still within spec)
That will pass tests but act up. Generally it occurs just as you say, right before the stop.
But first do step 2. If step 2 doesn't work have the mechanic take a real close look
at the sensors because one of them is out of calibration (or covered in metal filings)

2) Grime in the ABS computer connector (or the abs sensor connectors)

To clean the ABS sensors use a paper towel and a stick.
While your in there make sure the tone ring (toothed ring by the sensor)
isn't missing any teeth.

(based on the 93 ZJ)
Clean the connector on your ABS computer.
http://revbeergoggles.com/Fixes/computer-abs.jpg

Get a plastic bag, paper towel, a q-tip or ten, a zip tie
and some contact cleaner that's safe for plastic and a
bit of dilectric grease (sparkplug boot grease)

Disconnect the battery
Lift the latch and disconnect the harness
Take the airbox top and filter off. (this is your work sink)

Put the plastic bag in the airbox bottom, and some paper towels
now move the connector over the sink and open the shield, tap out
all the dirt and spray with cleaner (make sure it doesn't get on
the paint and if it does wipe it up pronto, it's like paint remover)

Clean the contacts on the ABS computer.

Put the shell back on and use the ziptie if the one on there broke.

Pack the dilectric grease into the connector and put it back on the
computer.

This fixes about 80% of all ABS light problems.

--
DougW

DougW

shelby did pass the time by typing:
> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?

Two things can do this.
1) ABS sensor just slightly out of cal (but still within spec)
That will pass tests but act up. Generally it occurs just as you say, right before the stop.
But first do step 2. If step 2 doesn't work have the mechanic take a real close look
at the sensors because one of them is out of calibration (or covered in metal filings)

2) Grime in the ABS computer connector (or the abs sensor connectors)

To clean the ABS sensors use a paper towel and a stick.
While your in there make sure the tone ring (toothed ring by the sensor)
isn't missing any teeth.

(based on the 93 ZJ)
Clean the connector on your ABS computer.
http://revbeergoggles.com/Fixes/computer-abs.jpg

Get a plastic bag, paper towel, a q-tip or ten, a zip tie
and some contact cleaner that's safe for plastic and a
bit of dilectric grease (sparkplug boot grease)

Disconnect the battery
Lift the latch and disconnect the harness
Take the airbox top and filter off. (this is your work sink)

Put the plastic bag in the airbox bottom, and some paper towels
now move the connector over the sink and open the shield, tap out
all the dirt and spray with cleaner (make sure it doesn't get on
the paint and if it does wipe it up pronto, it's like paint remover)

Clean the contacts on the ABS computer.

Put the shell back on and use the ziptie if the one on there broke.

Pack the dilectric grease into the connector and put it back on the
computer.

This fixes about 80% of all ABS light problems.

--
DougW

philthy

rust is building up on the tone wheels and it's making the air gap less
than it's suppose to be sending the wrong signals to the abs module
the early xj's were well known for this and the front of the jeep would
dance left to right and bac again when coming to a stop
a good scantool and a very close inspection is in order
a bad wheel bearing can do weird things too!

shelby@shelbyshreve.com wrote:

> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?
> Thanks,
> Shelby

philthy

rust is building up on the tone wheels and it's making the air gap less
than it's suppose to be sending the wrong signals to the abs module
the early xj's were well known for this and the front of the jeep would
dance left to right and bac again when coming to a stop
a good scantool and a very close inspection is in order
a bad wheel bearing can do weird things too!

shelby@shelbyshreve.com wrote:

> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?
> Thanks,
> Shelby

philthy

rust is building up on the tone wheels and it's making the air gap less
than it's suppose to be sending the wrong signals to the abs module
the early xj's were well known for this and the front of the jeep would
dance left to right and bac again when coming to a stop
a good scantool and a very close inspection is in order
a bad wheel bearing can do weird things too!

shelby@shelbyshreve.com wrote:

> Hello,
>
> Wondering if I could get some advice from you kind folks here. Over
> the last year and a half I have experienced intermittent problems with
> my ABS on my 97 Cherokee. When coming to a complete stop the ABS will
> kick in at maybe 5 mph right before the stop. It might do it a few
> times in a row then disappear for months at a time. Everything checks
> out when I take a look at the braking system, so I was stumped. I even
> have had the braking system professionally inspected a couple times
> right after the behavior, but everything checks out fine.....so I
> guessed it's one of those 'wait until it gets worse' kind of things.
>
> Lately however, it seems to be increasing in frequency. Yesterday
> after exhibiting the same behavior the ABS light came on. This leads
> me to think that it might be getting worse. Any ideas or
> troubleshooting advice for fixing this?
> Thanks,
> Shelby